diff options
Diffstat (limited to 'include/linux/jump_label.h')
| -rw-r--r-- | include/linux/jump_label.h | 53 |
1 files changed, 30 insertions, 23 deletions
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 48b9b2a82767..fdb79dd1ebd8 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -75,6 +75,7 @@ #include <linux/types.h> #include <linux/compiler.h> +#include <linux/cleanup.h> extern bool static_key_initialized; @@ -82,10 +83,9 @@ extern bool static_key_initialized; "%s(): static key '%pS' used before call to jump_label_init()", \ __func__, (key)) -#ifdef CONFIG_JUMP_LABEL - struct static_key { atomic_t enabled; +#ifdef CONFIG_JUMP_LABEL /* * Note: * To make anonymous unions work with old compilers, the static @@ -104,13 +104,9 @@ struct static_key { struct jump_entry *entries; struct static_key_mod *next; }; +#endif /* CONFIG_JUMP_LABEL */ }; -#else -struct static_key { - atomic_t enabled; -}; -#endif /* CONFIG_JUMP_LABEL */ #endif /* __ASSEMBLY__ */ #ifdef CONFIG_JUMP_LABEL @@ -221,26 +217,26 @@ extern struct jump_entry __start___jump_table[]; extern struct jump_entry __stop___jump_table[]; extern void jump_label_init(void); +extern void jump_label_init_ro(void); extern void jump_label_lock(void); extern void jump_label_unlock(void); extern void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type); -extern void arch_jump_label_transform_static(struct jump_entry *entry, - enum jump_label_type type); extern bool arch_jump_label_transform_queue(struct jump_entry *entry, enum jump_label_type type); extern void arch_jump_label_transform_apply(void); extern int jump_label_text_reserved(void *start, void *end); -extern void static_key_slow_inc(struct static_key *key); +extern bool static_key_slow_inc(struct static_key *key); +extern bool static_key_fast_inc_not_disabled(struct static_key *key); extern void static_key_slow_dec(struct static_key *key); -extern void static_key_slow_inc_cpuslocked(struct static_key *key); +extern bool static_key_slow_inc_cpuslocked(struct static_key *key); extern void static_key_slow_dec_cpuslocked(struct static_key *key); -extern void jump_label_apply_nops(struct module *mod); extern int static_key_count(struct static_key *key); extern void static_key_enable(struct static_key *key); extern void static_key_disable(struct static_key *key); extern void static_key_enable_cpuslocked(struct static_key *key); extern void static_key_disable_cpuslocked(struct static_key *key); +extern enum jump_label_type jump_label_init_type(struct jump_entry *entry); /* * We should be using ATOMIC_INIT() for initializing .enabled, but @@ -251,19 +247,19 @@ extern void static_key_disable_cpuslocked(struct static_key *key); */ #define STATIC_KEY_INIT_TRUE \ { .enabled = { 1 }, \ - { .entries = (void *)JUMP_TYPE_TRUE } } + { .type = JUMP_TYPE_TRUE } } #define STATIC_KEY_INIT_FALSE \ { .enabled = { 0 }, \ - { .entries = (void *)JUMP_TYPE_FALSE } } + { .type = JUMP_TYPE_FALSE } } #else /* !CONFIG_JUMP_LABEL */ #include <linux/atomic.h> #include <linux/bug.h> -static inline int static_key_count(struct static_key *key) +static __always_inline int static_key_count(struct static_key *key) { - return atomic_read(&key->enabled); + return raw_atomic_read(&key->enabled); } static __always_inline void jump_label_init(void) @@ -271,6 +267,8 @@ static __always_inline void jump_label_init(void) static_key_initialized = true; } +static __always_inline void jump_label_init_ro(void) { } + static __always_inline bool static_key_false(struct static_key *key) { if (unlikely_notrace(static_key_count(key) > 0)) @@ -285,11 +283,23 @@ static __always_inline bool static_key_true(struct static_key *key) return false; } -static inline void static_key_slow_inc(struct static_key *key) +static inline bool static_key_fast_inc_not_disabled(struct static_key *key) { + int v; + STATIC_KEY_CHECK_USE(key); - atomic_inc(&key->enabled); + /* + * Prevent key->enabled getting negative to follow the same semantics + * as for CONFIG_JUMP_LABEL=y, see kernel/jump_label.c comment. + */ + v = atomic_read(&key->enabled); + do { + if (v < 0 || (v + 1) < 0) + return false; + } while (!likely(atomic_try_cmpxchg(&key->enabled, &v, v + 1))); + return true; } +#define static_key_slow_inc(key) static_key_fast_inc_not_disabled(key) static inline void static_key_slow_dec(struct static_key *key) { @@ -308,11 +318,6 @@ static inline int jump_label_text_reserved(void *start, void *end) static inline void jump_label_lock(void) {} static inline void jump_label_unlock(void) {} -static inline int jump_label_apply_nops(struct module *mod) -{ - return 0; -} - static inline void static_key_enable(struct static_key *key) { STATIC_KEY_CHECK_USE(key); @@ -343,6 +348,8 @@ static inline void static_key_disable(struct static_key *key) #endif /* CONFIG_JUMP_LABEL */ +DEFINE_LOCK_GUARD_0(jump_label_lock, jump_label_lock(), jump_label_unlock()) + #define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE #define jump_label_enabled static_key_enabled |